the problem is i'm hearing a noise thats definitly comin from the head i thought at first that it was a bent valve that was stickin and hitting on the piston but then i realised that the car was not missing, now this noise only happens under 2000 rpm never above. its a loud rackling noise.so then i thought that it was that the oil pressure was low and the lifters was not getting addiquate oil so i bought a guage and the oil press is good.so i removed my valve cover, removed the cams to check the lifters and two of em wile pushin on them feels different from the rest.now i would of just bought a head if it was that easy but on this island just the duty alone will kill me so if any one has any advice please help and if its the lifters ,where can i get some.